From: Kefu Chai <kchai@redhat.com>
Date: Wed, 18 Nov 2020 10:34:38 +0000 (+0800)
Subject: crimson/osd: wait for min_epoch instead of map_epoch
X-Git-Tag: v16.1.0~438^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=refs%2Fpull%2F38127%2Fhead;p=ceph.git

crimson/osd: wait for min_epoch instead of map_epoch

osdmap_epoch is the latest osdmap of the client, it is not the minimum
osdmap epoch required to serve the request from the client with this
osdmap.

as a matter of fact, `MOSDOp` inherits from `MOSDFastDispatchOp`.
the `MOSDFastDispatchOp::get_min_epoch()` returns `get_map_epoch()`, and
`MOSDOp` does not override `get_min_epoch()`.

`ClientRequest` is designed to handle `MOSDOp`. so, there is no need
to wait for `m->get_map_epoch()` osdmap before moving further, and more
importantly, we should wait until PG is updated with min_epoch osdmap.

Signed-off-by: Kefu Chai <kchai@redhat.com>
---

diff --git a/src/crimson/osd/osd_operations/client_request.cc b/src/crimson/osd/osd_operations/client_request.cc
index f2fa0e205075..fbd116b5f312 100644
--- a/src/crimson/osd/osd_operations/client_request.cc
+++ b/src/crimson/osd/osd_operations/client_request.cc
@@ -76,7 +76,7 @@ seastar::future<> ClientRequest::start()
 	  handle.enter(pp(pg).await_map)
 	).then([this, &pg]() mutable {
 	  return with_blocking_future(
-	    pg.osdmap_gate.wait_for_map(m->get_map_epoch()));
+	    pg.osdmap_gate.wait_for_map(m->get_min_epoch()));
 	}).then([this, &pg](auto map) mutable {
 	  return with_blocking_future(
 	    handle.enter(pp(pg).wait_for_active));